Acute graft-versus-host disease (aGVHD) complicates allogeneic hematopoietic stem cell transplantation (HSCT), and is treated with topical and/or systemic corticosteroids. Systemic corticosteroids and aGVHD damage thymic tissue. We compared thymopoietic effect of topical steroid therapy, corticosteroids and extracorporeal photopheresis (ECP) in 102 pediatric allogeneic HSCT patients.

We categorized patients into 4 groups: - no aGVHD, aGVHD treated with topical or systemic steroid, or ECP. Naïve CD4⁺ CD45RA⁺ CD27⁺ T-lymphocyte values at 3, 6, 9, 12 months post-HSCT were recorded: for ECP patients, values were recorded at 3, 6, 9, 12 months during ECP. Differences were compared using the Kruskal-Wallis test.

41 patients had no aGVHD, 23 had aGVHD treated topically or systemically (25), 13 received ECP. Rate of thymopoiesis was significantly different between all groups at all time-points post-transplant (p = 0.002, p < 0.001, p < 0.001, p = 0.001 respectively).

Even mild aGVHD impairs thymopoiesis. Worst recovery was in ECP patients. Earlier institution of ECP may speed thymic recovery.

急性移植物抗宿主病（aGVHD）使同种异体造血干细胞移植（HSCT）复杂化，并接受局部和/或全身性皮质类固醇激素治疗。全身性皮质类固醇和aGVHD会损伤胸腺组织。我们比较了102名小儿同种异体造血干细胞移植患者的局部类固醇治疗，皮质类固醇和体外光采术（ECP）的胸腺生成作用。

我们将患者分为4组：-无aGVHD，经局部或全身性类固醇或ECP治疗的aGVHD。记录HSCT后3、6、9、12个月的幼稚CD4 ⁺  CD45RA ⁺  CD27 ⁺ T淋巴细胞值：对于ECP患者，在ECP期间3、6、9、12个月记录值。使用Kruskal-Wallis检验比较差异。

41例无aGVHD的患者，23例经局部或全身治疗的aGVHD（25），13例接受了ECP。两组在移植后所有时间点的胸腺生成率显着不同（分别为p = 0.002，p <0.001，p <0.001，p = 0.001）。

甚至轻度的aGVHD也会损害胸腺生成。ECP患者的恢复最差。早期建立ECP可能会加速胸腺的恢复。